PP422 - Over-the-Counter Hearing Aids and Listening Effort: A Pilot Study Using Pupillometry

Abstract:
Over-the-counter (OTC) hearing aids are a recent class of hearing aids intended for adults with mild-to-moderate hearing loss. While recent studies have suggested that OTC hearing aids can improve speech recognition, their impact on reducing listening effort remains unclear. Listening effort is a significant challenge for older listeners with hearing loss, who may use OTC hearing aids to alleviate this cognitive load. This study explores the potential of OTC hearing aids to reduce listening effort using pupillometry during a speech-in-noise task with 11 older adults with mild-to-moderate hearing loss.

Summary:
Objectives and Rationale
Listening effort is a significant challenge for older listeners with hearing loss. Older listeners with hearing loss have been demonstrated to expend greater than typical cognitive resources to recognize speech, especially in challenging listening environments. Pupillometry, an objective measure of listening effort, has been used to quantify the mental resources required to understand speech in noisy environments. Previous investigations have demonstrated the benefits of professionally-fit amplification to reduce the listening effort needed for speech recognition.

A new classification of hearing aids within the Food and Drug Administration (FDA) are over-the-counter (OTC) hearing aids, intended for adults with mild-to-moderate hearing loss. While previous studies have suggested that OTC hearing aids improve speech recognition-in-noise, it is unclear whether OTC hearing aids also reduce the cognitive load associated with speech perception. The impact of OTC hearing aids on listening effort is crucial to consider, as the perceived effort required to understand speech can be a key factor in determining whether an individual will initiate or maintain active participation in communication interactions.

To address this gap in the literature, the objective of this study was to investigate whether OTC hearing aids can reduce listening effort in two speech-in-noise conditions, using pupillometry as an objective measure of listening effort.

Design
Eleven adults (mean age = 67 years; age range: 49–75 years) with mild-to-moderate sensorineural hearing loss (four-frequency pure-tone average (PTA) mean = 36 dB HL, SD = 8.8 dB HL) participated in this study. Participants were fitted with a pair of pre-set OTC hearing aids (i.e., OTCs with manufacturer-defined programs), in the following programs: one of two default programs (Mild and Moderate) and a Noise-Reduction (NR) program. Each participant was assigned to the Mild or Moderate default program based on real-ear aided response measurements using NAL-NL2 prescriptive targets.

Pupillometry was conducted using the SR Research Eyelink 1000 infrared video-based eye tracker. Speech materials from the Repeat and Recall test were used, with low- and high-context sentences calibrated to 77 dB SPL with steady-state noise presented at +5 and +10 dB signal-to-noise ratios (SNRs). Sentences were presented at 0° azimuth in front of the participant, with noise presented at 180° azimuth behind them. Participants were instructed to fixate on a cross on a computer monitor and repeat the sentence 3 seconds after its presentation. Three hearing aid conditions were tested: unaided, OTC hearing aids in the default program, and OTC hearing aids in the NR program. Data analysis focused on speech recognition, peak pupil dilation, and time-series analysis using generalized additive mixed modeling to compare responses between SNR conditions for each of the hearing aid conditions and sentence contexts.

Results
Data collection is complete, and data analysis is underway, with the results expected prior to February 2025.

Conclusions
Listening effort is an aspect of speech communication that older listeners with hearing loss may seek to improve with the use of OTC hearing aids. Our findings will provide preliminary data informing whether OTC hearing aids can reduce the cognitive load required for speech recognition-in-noise.